Keratosis Pilaris · What Is It, Causes, Treatment, and More

Keratosis pilaris, also known as follicular keratosis, is a common, harmless skin condition that causes small bumps to develop on the upper arms, thighs, cheeks, and buttocks but not the palms of the hands or soles of the feet. The bumps can go away on their own over time, often fading by the age of 30. Fifty to 80% of teenagers and 40% of adults will develop these bumps on their skin.

Keratosis pilaris is caused by a buildup of dead skin cells and keratin -- a hard protein found in skin, hair, and nails -- that clogs the pores around a hair follicle. Keratosis pilaris is seen more commonly in individuals with a family history of asthma, allergies, or eczema. Additionally, dry skin may worsen the symptoms of keratosis pilaris. Side effects of certain medications can also cause keratosis pilaris, as in the case of vemurafenib, a chemotherapy medication used to treat melanoma.   

Keratosis pilaris is not contagious, so it cannot be transmitted via direct contact with someone who has it. 

There is a possible genetic component of keratosis pilaris. It can be linked to certain genetic traits, such as lighter skin tone. There is also increased risk for individuals who have certain conditions, including eczema and asthma; however, it is unclear if these conditions are genetically inherited. Lastly, those with ichthyosis vulgaris, a genetic condition that causes chronic dry, scaly skin, are more prone to developing keratosis pilaris. Ichthyosis vulgaris is common in younger people and worsens around the age of puberty. 

The signs and symptoms of keratosis pilaris include itchy or dry skin with painless bumps on the backs of the arms, legs, face, or buttocks. The skin can feel rough at the site of the bumps and may become red if the bumps are irritated, such as when you rub your skin. Symptoms can worsen with the seasons, particularly in the winter months when the air is drier, and usually present with a greater number of bumps that are more irritated. 

Keratosis pilaris is commonly diagnosed upon physical examination by a healthcare provider. Diagnosis includes evaluating the location and characteristics of the bumps. Medical testing is usually not required for diagnosis, but in the case that the clinician is unsure of the diagnosis, a sample of the skin can be taken and examined by microscopy to rule out other skin conditions.

Keratosis pilaris presents as bumps that can be skin-colored, red, white, brown, or dark brown, somewhat depending on the natural color of the individual’s skin. It is often called “chicken skin” due to its similar appearance to goosebumps. 

Since keratosis pilaris is harmless, it does not require treatment. However, lifestyle modifications that reduce dry skin can help to minimize the appearance of keratosis pilaris. Lifestyle approaches include taking shorter showers in lukewarm, rather than hot, water, humidifying indoor air, exfoliating skin with a loofah, and moisturizing often. If itchiness and dryness of the skin become especially uncomfortable, certain additional treatments can help. 

Over-the-counter and prescription-strength moisturizing creams can be used to soothe dry skin and reduce the presence of bumps. The ingredients of creams that may be used to treat keratosis pilaris can include urea, lactic acid, alpha hydroxy acid, glycolic acid, or a retinoid (e.g., adapalene, retinol, tazarotene, or tretinoin). It is recommended to apply such creams within five minutes after showering or bathing, while the skin is still damp, and improvement is typically seen within 4 to 6 weeks of beginning usage. Side effects of the creams may include skin dryness, tightness, peeling, and redness. A healthcare professional should be consulted prior to using prescription medications. Other medications, such as corticosteroid creams, can be applied to affected areas to soften the bumps and reduce redness and inflammation. 

Keratosis pilaris is a harmless skin condition that presents as bumps on the upper arms, legs, cheeks, and buttocks. The bumps are typically skin-colored and painless, and they feel rough to the touch, due to keratin buildup that blocks the opening of pores. It is common to develop keratosis pilaris in areas of the body where the skin is dry, so moisturizing lotions and corticosteroid creams may be part of an individual’s treatment for keratosis pilaris. Symptoms should resolve within 4 to 6 weeks after initiating treatment. It is not necessary to treat the condition if symptoms do not significantly impact the individual. Moreover, symptoms may resolve over time without treatment. Keratosis pilaris is not contagious, and it is linked to certain genetic traits, such as lighter skin tone. If an individual is concerned about having keratosis pilaris, or a similar skin condition, a healthcare professional may be consulted to discuss an individualized course of treatment.